My research on metamaterials involves the exploration of electromagnetic resonances in nano-structures. This mechanism is very general; it applies to metallic and other materials systems (depending on the frequency regime of interest). The goal is to create artificial materials with novel electromagnetic properties by replacing intrinsic electronic states, as they exist in conventional materials, with engineered nano-scale electromagnetic resonances.
In my research on metamaterials, I co-invented a mechanism for designing high-refractive index metamaterials by exploiting the existence of nano-scale propagating modes in metallic systems. As an example, I investigated a metal film with a periodic arrangement of cut-through subwavelength slits. This system can be regarded as a dielectric slab with a frequency-independent refractive index entirely controlled by geometry. Arbitrary high indices can be straightforwardly synthesized. Such a capability is important for confinement and enhancement of weak optical signals generated by small sample volumes. More fundamentally, refractive index is commonly regarded as an intrinsic material property that is directly related to the underlying electronic states. This work adds evidence to the potential of replacing electronic states with electromagnetic resonances.